Thermocouple for pilot burners



W. A. RAY

THERMOCOUPLE FOR PILOT BURNERS Filed Feb. 24, 1945 INVENTOR VV/l/fam 4. Pay B ATTORNEY March so, 1948.

ends of the conductors.

Patented Mar; 30, 1948 }UNITED' STATES PATENT OFFICE 4 THIERMOCOUPLE For; PILOT BURNEBS -William A. BaylGlendalefCalitQ, asslgnor to General Controls 00., a corporation Application February 24, 1945, Serial No. 579,646

This invention relates to a thermocouple structure, and more particularly to astructure of this character that may be used to generate a controlling electric current .by the aid of a burner flame.

The generation of electrical energy is effected by joining a pair of dissimilar conductors, and heating the joint or junction above that of'other The power generated is a function of the difference in temperature at the hot junction and at the cold junctions. The

hot junction, for the control purposes, is disposed in the burner flame. By appropriate shielding, th cold junction temperatures can be maintained considerably below that of the hot junction.

1 Claim- (Cl. 136-4) priate manner to appropriate leads, and these joints are the cold junctions. It is one of the objects of this invention to improve thermocouple structures of this character.

It is another object of this invention to provide a structure that is simple and inexpensive 1 to manufacture;

In order to shield the cold junctions from the burner flame, it has been proposed to use a sheath surrounding the cold junctions. In this way, the cold junctions can be placed quite close to the hot junction, .with an attendant saving in the length of the thermoelectric conductors. It is another object of this invention to make it possible in a simple manner to provide a. shield v for at least one of the cold junctions. and which serves as well to support the conductors in a simple manner.

Referring to the drawings:

Figure 1 is a view, mainly in longitudinal section, of the thermocouple structure incorporating the invention;

' Fig. 2 is a side elevation thereof and Figs. 3, 4, 5, and 6 are enlarged sectional views, taken along correspondingly numbered planes of Fig. 1.

Two dissimilar conductors are employed to form a thermoelectric couple.

One of these conductors has a head portion I through which an aperture 2 is formed. Attached to the head portion I is a hollow extension 5 that includes the narrow portion 4. The head I is quite long. providing a long aperture 2.

This conductor, including its extensions 4 and 5, may be formed, for example, of Chromel.

Another thermoelectric conductor 6 (which may be Copel) is provided, one end of which extends into the aperture 2, thus forming a hot junction. In order to ensure intimate electrical contact between the two conductors l and 6. the 1 upper end of conductor I may be originally formed with a, beveled projection I, as indicated in dotted lines. This beveled projection may extend beyond the upper end of the conductor 6 and may be melted down to form a fused joint over the top of conductor 6.

' The Copel conductor 6 is adequately supported, due to the fact that the end accommodated in the aperture 2 is quite long. Furthermore, it is shown as provided with an appropriate heat resisting insulation la yer 8 formed, for example, of asbestos (see also Figs. 4 and 5). It is joined to a, copper lead member 9, as by the aid of a split metallic sleeve l0, which engages the -bared ends of the conductor 6 and the lead 9. This band l0 may be brazed, or otherwise firmly joined, to

'the contiguous ends of the conuductor 6 and lead 9. I

.The extension 5 is telescoped over a hollow connector Ii, thereby providing an electrical connection to a lead l2. This electrical connection forms one of the cold junctions: the other cold junction is formed between contiguous ends of the conductor 9 and the conductor 6 connected by the band or sleeve ill.

A flexible armor l3, formed of convoluted metal, is preferably disposed over the lower end or the conductor 6, as well as over the leads 9 and 12. This armor may extend upwardly into the lower end of the connector II. This connector H, as shown most clearly inFig. 2, may be pinched as illustrated at l4 to hold the flexible armor l3 tightly in place within the member H.

. ly. In this way, the lead I2 is adequately supported and is in good electrical contact with the interior of the hollow connector II.

In use, the head I is intended to be inserted into a. pilot flame; thereby the hot junction is heated. The skirt portion 4, 5 shields the cold junctions from the flame and ensures that a large temperature difierential can be maintained between the hot junction and the cold junctions.

As clearly shown in Figs. 1 and 6, a sleeve l5 3 4 0! insulating material surrounds the bend l0, hollow connector being formed to hold the said insulstingthe band it item the armor ll. lead firmly in relation to the connector.

The inventor claims: I WILLIAM A. RAY. In a thermocouple structure: a first thermoelectriccoiaducltzoi'l hevinc gil apert nre gdjacent 5 REFERENCES CITED one end an a. o ow exte on at t e ot erend: The mu m ref a second g f g fi gg rl rt g me of this page: e ences are ol record in the the hollow ex us on an a, g on end se e into the aperture; a hollow connector teleacop- UNITED STATES'PATENTS ing into the hollow extension: 9. lead connected 10 Number Name Date to the interior oi. said connector; a layer of in- 2,267,742 Mantz Dec. 30, 1941 sulation on said second conductor: and a flexible 2,318,822 Wantz May 11, 1943 armor encompassing the said lead and the 866- 2,339,809 Ray Jan. 25, 1944 0nd conductor; said hollow extension and the 

